Shark protection activist, filmmaker Stewart goes missing off Florida

(Reuters) - A search for award-winning Canadian filmmaker Rob Stewart, an environmental activist campaigning to protect sharks from being killed, entered its third day on Thursday after he went missing while diving off Florida, the U.S. Coast Guard said.

The Coast Guard received a call on Tuesday afternoon of Stewart going missing near Alligator Reef, located a few miles off the Florida Keys. It did not provide details about how Stewart, 37 and an experienced scuba diver, went missing.

The U.S. Navy, Florida wildlife officials and a county sheriff have joined the Coast Guard in the search for Stewart, using ships, helicopters and dive teams, the Coast Guard said.

Stewart's sister, Alexandra Stewart, was quoted by the Toronto Star newspaper as saying her brother was in Florida to film a new documentary called "Sharkwater: Extinction." He disappeared following an incident that left his diving partner unconscious, it reported her as saying.

“He had surfaced and gave the 'OK' sign and then he was gone," Alexandra Stewart was quoted as saying on Wednesday.

Rob Stewart's 2006 documentary "Sharkwater" was aimed at exposing the shark hunting industry that was feeding demand for fins, a delicacy in Chinese cuisine. The hunting has ravaged shark populations and the film was part of a campaign that helped persuade some governments to crackdown on finning.

With finning, typically the fins are cut off and the live shark is tossed back into the sea. Unable to swim properly, the shark suffocates or is killed by predators.

Stewart said his new film was looking at other ways that as many as 80 million sharks are being harvested each year for items ranging from cosmetics to pet food.

"Sharks are sophisticated, intelligent and often shy creatures that aren’t interested in eating humans," he said in a video seeking funding for his new movie.